1. Field of the Invention
The present invention relates to a converter, a server system, a conversion method and a program. In particular, the present invention relates to a converter, a server system, a conversion method and a program for generating a batch processing program for collectively processing a plurality of job requests.
2. Description of Related Art
In a server system for implementing a web application and a banking system or the like, online transaction processing is performed in which a server processes a job request provided from a client and then replies to the client with a result of the processing. Such a server system needs to instantly process a vast amount of job requests, so that the server system has become a large scale system.
In such online transaction processing performed by the server system, since each processing is independently performed for each job request, various overheads are redundantly needed during a series of processings for multiple job requests. In a case of executing online transaction processing involving access to a database server, for example, an application server needs to start an application program and to communicate with the database server in response to every job request.
In order to overcome such inconvenience, a server system that executes a batch program for collectively processing an appropriate number of job requests has been proposed (“Development of System Architecture and Middleware Product Achieving Large Scale and High Speed Transaction Processing (originally in Japanese, daikibo kousoku transaction shyori wo jitsugen suru system architecture narabini middleware seihin wo kaihatu)” by NEC Corporation, press release announced on the official website of NEC Corporation on Sep. 26, 2007, Internet URL: <http://www.nec.co.jp/press/ja/0709/2601.html>). Such a server system only needs to make a single access to a database server for each plurality of job requests in a collective manner. Accordingly, the frequencies of starting an application program and of communications with a database server can be reduced. As a result, such a server system enables online transaction processing with an improvement in the throughput of the entire system by reducing processing overheads, which might be redundantly required to perform a series of multiple processings for each plurality of job requests.
A technique for collectively processing a plurality of queries by reconfiguring a program itself of a database server is proposed in Non-Patent Document 2 (Harizopoulos, S. and Ailamaki, A., “Improving instruction cache performance in OLTP,” “ACM Trans. Database Syst. 31, 3 (September 2006),” 887-920). According to such a technology, processing throughput in a database server can be improved.
For the server system described in Non-Patent Document 1, however, a batch program for collectively processing a plurality of job requests has to be newly developed, which results in a large amount of development work and costs. In addition, since the development of the batch program requires consistency among job requests, the development is difficult as compared with development of an application program causing a server system to execute processing of a single job request. Furthermore, the technology described in Non-Patent Document 2 requires a change in the program itself of a database server to a large extent, so that it is difficult to apply the technology to the existing database servers.